Safety device fob motors



NOV '15, 1933- G. L. HILBERT ET AL 2,136,504

SAFETY DEVICE FOR MOTORS Filed May 25, 1957 Mmm Attorneys Patented Nov.15, 1938 UNITED STATES PATENT OFFICE SAFETY DEVICE FOR MOTORSApplication May 25, 1937, Serial No. 144,724

1 Claim.

This invention relates to a safety device for internal combustionmotors, the general object oi the invention being to provide means forinterrupting the ignition circuit of the motor if the oil pressureshould cease or reach a dangerous point.

This invention also consists in certain other features of constructionand in the combination and arrangement of several parts, to behereinafter fully described, illustrated in the accompanying drawing andspecifically pointed out in the appended claim.

In describing the invention in detail, reference will be had to theaccompanying drawing wherein like characters denote like orcorresponding parts throughout the several views, and in which- Figure lis a rear elevation of the parts in section showing one form of theinvention.

Figure 2 is a irontv view of Figure 1.

Figure 3 is a top plan view thereof.

Figure 4 is an elevation showing a modied form of the invention.

In this drawing, the. numerals I and 2 indicate a pair of disk-likeparts fastened together by the screws 3 with a diaphragm 4 between them,the parts being recessed to form a chamber when fastened together withthe diaphragm dividing the chamber into upper and lower portions. Thedisk I is formed with a reduced upper part 5 having a chamber I5 thereinwhich is in communication with the rst-mentioned chamber and a stem Ipasses through the part 5 and has an enlargement 8 at its lower endwhich bears against the upper face of the diaphragm and is held in thisposition by a spring 9 which encircles the stem and bears against thetop of the chamber 6. The member 2 is provided with a reduced lower part2 which is bored to receive a pipe IU which is connected with thelubricating system of the motor so that when the pump is in operationsome of the oil will pass through the pipe I into the lower part of thechamber and thus act on the diaphragm to raise the same and the stem 1against the action of the spring 9.

A spring strip I I is fastened to the upper portion of the part as shownat I2 and carries a contact I3 at its free end for engaging a similarcontact I4 carried by a bracket I 5 attached to the part 5. The bracketis insulated from the part 5 and its contact I4 is connected to a partof the ignition circuit of the motor while the strip II is grounded onthe device. Thus when the motor is idle the ignition circuit is groundedbut when the motor is in operation the oil pressure acting on thediaphragm will raise the stem 'I and cause the same to lift the strip IIso that the contacts I3 (Cl. 20D-83) and III are out of engagement andthus the ignition circuit is not grounded and the engine can operate inthe usual manner.

In order to prevent the device from interfering with the starting of themotor I provide a magnet I6 which is supported by but insulated from theupright frame II which is attached to the body of the device, the magnetbeing grounded to the frame as shown at I8 and being connected to thestarter switch of the engine by the connections I9. The magnet is placedover the strip II so that when it is energized by the closing of thestarter switch it will lift the strip II, thus separating the contactsI3 and I4 so that the ignition circuit will be completed. Then when theengine starts the oil pressure will lift the stern 'I so that the stripII will be held in raised position even after the magnet I5 becomesdeenergized.

In the modification shown in Figure 4 the parts are arranged to breakthe ignition circuit when the oil pressure becomes low and in this formof the invention the strip I I extends below the bent part of a bracketI5 so that normally the contacts are separated. As the parts of theignition circuit are connected with these contacts the circuit is brokenwhen the member II is in its normal position. However, when the engineis in operation the oil pressure operating on the diaphragm will causethe stem of the diaphragm to raise the strip II so as to place the twocontacts together and thus complete the circuit to the spark plug.However, if the pressure should drop to permit the diaphragm to movedownwardly the strip II will also move downwardly and thus break thecircuit.

We also provide a magnet I B connected with the starting circuit toattract the strip II and hold it in raised position when the starterswitch is closed so as to permit the initial starting of the motor. Aswill be seen the modiiication is similar to the first form of theinvention excepting the reversing 0i the contacts which act to break thecircuit when the oil pressure is low instead of grounding the circuit asshown in Figure 1.

It is thought from the foregoing description that the advantages andnovel features of the invention will be readily apparent.

It is to be understood that changes may be made in the construction andin the combination and arrangement of the several parts, provided thatsuch changes fall within the scope -of the appended claim.

What is claimed is:

A switch for use in conjunction with the ignition circuit, starterswitch, and pressure oiling directions into and from closing positions,respec? tively, and both pressure operative and electromagnetic meansfor moving said movable member in one direction, the pressure operativemeans for connection in said pressure system, and the electro-magneticmeans for control by the starter switch.

GEORGE L. HILBERT. ARTHUR E. WEST. JAY H. WEST.

